The present invention relates to a clutch group, a flywheel power take-off, an intermediate power take-off and a gearbox power take-off comprising said clutch group.
In other words the clutch group according to the present invention is suitable to be applied to industrial vehicle power take-offs. In this description, “industrial vehicle” means a vehicle such as a truck, articulated vehicle, a road tractor or a farm machine.
Power take-off solutions in industrial vehicles have long been known.
For example, the patents on behalf of the Applicant IT1277770 and IT1314722 show some power take-off solutions suitable to be interposed between the engine group and/or gearbox speed change unit and rear axle, in which the command of the actuation of the outputs for withdrawing power is obtained by clutch groups.
In addition, flywheel power take-off solutions are known, i.e. mounted between the engine group and the gearbox speed change unit, in which the actuation of the outputs for withdrawing power is obtained by clutch groups.
The aim of power take-offs, both intermediate and flywheel, is to allow a withdrawal of power which is then exploited in specific appropriate uses, such as moving pumps, fans, blowers or similar components included in the industrial vehicle depending on its scope of application.
The main need of power take-offs is thus to withdraw large quantities of power, while minimising their dimension, a typical factor in the automotive sector.
Currently this need is resolved by proposing solutions for clutch groups presenting a hydraulic drive.
However, such known clutch group solutions have a plurality of issues or restrictions related to the presence of oil, which make them particularly complex.
Firstly, because oil, unlike the air, is basically incompressible, such known clutch groups have means, valves and/or pump groups for the purpose of achieving a predetermined command modularity.
Secondly, oil has a much higher specific gravity and therefore, when the clutch is rotating, on account of the centrifugal force is difficult to expel from the command chamber of known clutch groups. These therefore provide, in order to ensure proper expulsion of the oil, return springs acting on the oversized clutch discs or use dual effect hydraulic commands.